The present disclosure relates to optical elements and semiconductor light emitting devices using the optical elements, and particularly relates to optical elements capable of emitting light with directivity, and semiconductor light emitting devices using the optical elements.
In recent years, semiconductor light emitting elements, such as high-efficiency and high-output light emitting diodes (LEDs) using a gallium nitride material or a gallium arsenide material, have been commercialized. Accordingly, display light sources using the semiconductor light emitting elements have also been commercialized. As the display light sources using the semiconductor light emitting elements, edge-lit light sources in which light from an LED placed on a side of the screen is guided to the entire screen of the display device, using a light guide plate placed on the back side of the screen have been gaining attention. A further reduction in energy loss of the display light sources by using a semiconductor laser element which is superior in directivity to LEDs is being considered, as well (see, e.g., Japanese Patent Publication No. 2009-158620).